[dpdk-dev] [RFC] librte_pmd_null: Add null PMD

[mukawa@igel.co.jp]

From: Tetsuya Mukawa <mukawa@igel.co.jp>

'null PMD' is a virtual device driver particulary designed to measure
performance of DPDK applications and DPDK PMDs. When an application call rx,
null PMD just allocate mbufs and return those. Also tx, the PMD just free
mbufs.

The PMD has following options.
- size: specify packe size allocated by RX. Default packet size is 64.
- copy: specify 1 or 0 to enable or disable copy while RX and TX.
	Default value is 0(disbaled).
	This option is used for emulating more realistic data transfer.
	Copy size is equal to packet size.

Signed-off-by: Tetsuya Mukawa <mukawa@igel.co.jp>
---
 config/common_bsdapp               |   5 +
 config/common_linuxapp             |   5 +
 lib/Makefile                       |   1 +
 lib/librte_pmd_null/Makefile       |  58 +++++
 lib/librte_pmd_null/rte_eth_null.c | 474 +++++++++++++++++++++++++++++++++++++
 5 files changed, 543 insertions(+)
 create mode 100644 lib/librte_pmd_null/Makefile
 create mode 100644 lib/librte_pmd_null/rte_eth_null.c

diff --git a/config/common_bsdapp b/config/common_bsdapp
index 645949f..a86321f 100644
--- a/config/common_bsdapp
+++ b/config/common_bsdapp
@@ -226,6 +226,11 @@ CONFIG_RTE_LIBRTE_PMD_PCAP=y
 CONFIG_RTE_LIBRTE_PMD_BOND=y
 
 #
+# Compile null PMD
+#
+CONFIG_RTE_LIBRTE_PMD_NULL=y
+
+#
 # Do prefetch of packet data within PMD driver receive function
 #
 CONFIG_RTE_PMD_PACKET_PREFETCH=y
diff --git a/config/common_linuxapp b/config/common_linuxapp
index 5bee910..e3bd8c0 100644
--- a/config/common_linuxapp
+++ b/config/common_linuxapp
@@ -254,6 +254,11 @@ CONFIG_RTE_LIBRTE_PMD_BOND=y
 CONFIG_RTE_LIBRTE_PMD_XENVIRT=n
 
 #
+# Compile null PMD
+#
+CONFIG_RTE_LIBRTE_PMD_NULL=y
+
+#
 # Do prefetch of packet data within PMD driver receive function
 #
 CONFIG_RTE_PMD_PACKET_PREFETCH=y
diff --git a/lib/Makefile b/lib/Makefile
index 10c5bb3..61d6ed1 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -50,6 +50,7 @@ DIRS-$(CONFIG_RTE_LIBRTE_PMD_PCAP) += librte_pmd_pcap
 DIRS-$(CONFIG_RTE_LIBRTE_VIRTIO_PMD) += librte_pmd_virtio
 DIRS-$(CONFIG_RTE_LIBRTE_VMXNET3_PMD) += librte_pmd_vmxnet3
 DIRS-$(CONFIG_RTE_LIBRTE_PMD_XENVIRT) += librte_pmd_xenvirt
+DIRS-$(CONFIG_RTE_LIBRTE_PMD_NULL) += librte_pmd_null
 DIRS-$(CONFIG_RTE_LIBRTE_HASH) += librte_hash
 DIRS-$(CONFIG_RTE_LIBRTE_LPM) += librte_lpm
 DIRS-$(CONFIG_RTE_LIBRTE_ACL) += librte_acl
diff --git a/lib/librte_pmd_null/Makefile b/lib/librte_pmd_null/Makefile
new file mode 100644
index 0000000..e017918
--- /dev/null
+++ b/lib/librte_pmd_null/Makefile
@@ -0,0 +1,58 @@
+#   BSD LICENSE
+#
+#   Copyright (C) 2014 Nippon Telegraph and Telephone Corporation.
+#   All rights reserved.
+#
+#   Redistribution and use in source and binary forms, with or without
+#   modification, are permitted provided that the following conditions
+#   are met:
+#
+#     * Redistributions of source code must retain the above copyright
+#       notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above copyright
+#       notice, this list of conditions and the following disclaimer in
+#       the documentation and/or other materials provided with the
+#       distribution.
+#     * Neither the name of Intel Corporation nor the names of its
+#       contributors may be used to endorse or promote products derived
+#       from this software without specific prior written permission.
+#
+#   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+#   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+#   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+#   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+#   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+#   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+#   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+#   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+#   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+#   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+#   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+include $(RTE_SDK)/mk/rte.vars.mk
+
+#
+# library name
+#
+LIB = librte_pmd_null.a
+
+CFLAGS += -O3
+CFLAGS += $(WERROR_FLAGS)
+
+#
+# all source are stored in SRCS-y
+#
+SRCS-$(CONFIG_RTE_LIBRTE_PMD_NULL) += rte_eth_null.c
+
+#
+# Export include files
+#
+SYMLINK-y-include +=
+
+# this lib depends upon:
+DEPDIRS-$(CONFIG_RTE_LIBRTE_PMD_NULL) += lib/librte_mbuf
+DEPDIRS-$(CONFIG_RTE_LIBRTE_PMD_NULL) += lib/librte_ether
+DEPDIRS-$(CONFIG_RTE_LIBRTE_PMD_NULL) += lib/librte_malloc
+DEPDIRS-$(CONFIG_RTE_LIBRTE_PMD_NULL) += lib/librte_kvargs
+
+include $(RTE_SDK)/mk/rte.lib.mk
diff --git a/lib/librte_pmd_null/rte_eth_null.c b/lib/librte_pmd_null/rte_eth_null.c
new file mode 100644
index 0000000..1a81843
--- /dev/null
+++ b/lib/librte_pmd_null/rte_eth_null.c
@@ -0,0 +1,474 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright (C) 2014 Nippon Telegraph and Telephone Corporation.
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <rte_mbuf.h>
+#include <rte_ethdev.h>
+#include <rte_malloc.h>
+#include <rte_memcpy.h>
+#include <rte_dev.h>
+#include <rte_kvargs.h>
+
+#define ETH_NULL_PACKET_SIZE_ARG	"size"
+#define ETH_NULL_PACKET_COPY_ARG	"copy"
+
+static unsigned default_packet_size = 64;
+static unsigned default_packet_copy;
+
+static const char const *valid_arguments[] = {
+	ETH_NULL_PACKET_SIZE_ARG,
+	ETH_NULL_PACKET_COPY_ARG,
+	NULL
+};
+
+struct pmd_internals;
+
+struct null_queue {
+	struct pmd_internals *internals;
+
+	struct rte_mempool *mb_pool;
+	struct rte_mbuf *dummy_packet;
+
+	rte_atomic64_t rx_pkts;
+	rte_atomic64_t tx_pkts;
+	rte_atomic64_t err_pkts;
+};
+
+struct pmd_internals {
+	unsigned packet_size;
+	unsigned packet_copy;
+	unsigned numa_node;
+
+	unsigned nb_rx_queues;
+	unsigned nb_tx_queues;
+
+	struct null_queue rx_null_queues[1];
+	struct null_queue tx_null_queues[1];
+};
+
+
+static struct ether_addr eth_addr = { .addr_bytes = {0} };
+static const char *drivername = "Null PMD";
+static struct rte_eth_link pmd_link = {
+	.link_speed = 10000,
+	.link_duplex = ETH_LINK_FULL_DUPLEX,
+	.link_status = 0
+};
+
+static uint16_t
+eth_null_rx(void *q, struct rte_mbuf **bufs, uint16_t nb_bufs)
+{
+	int i;
+	struct null_queue *h = q;
+	unsigned packet_size = h->internals->packet_size;
+
+	for (i = 0; i < nb_bufs; i++) {
+		bufs[i] = rte_pktmbuf_alloc(h->mb_pool);
+		if (!bufs[i])
+			break;
+		bufs[i]->data_len = (uint16_t)packet_size;
+		bufs[i]->pkt_len = packet_size;
+		bufs[i]->nb_segs = 1;
+		bufs[i]->next = NULL;
+	}
+
+	rte_atomic64_add(&(h->rx_pkts), i);
+
+	return i;
+}
+
+static uint16_t
+eth_null_copy_rx(void *q, struct rte_mbuf **bufs, uint16_t nb_bufs)
+{
+	int i;
+	struct null_queue *h = q;
+	unsigned packet_size = h->internals->packet_size;
+
+	for (i = 0; i < nb_bufs; i++) {
+		bufs[i] = rte_pktmbuf_alloc(h->mb_pool);
+		if (!bufs[i])
+			break;
+		rte_memcpy(rte_pktmbuf_mtod(bufs[i], void *), h->dummy_packet,
+					packet_size);
+		bufs[i]->data_len = (uint16_t)packet_size;
+		bufs[i]->pkt_len = packet_size;
+		bufs[i]->nb_segs = 1;
+		bufs[i]->next = NULL;
+	}
+
+	rte_atomic64_add(&(h->rx_pkts), i);
+
+	return i;
+}
+
+static uint16_t
+eth_null_tx(void *q, struct rte_mbuf **bufs __rte_unused, uint16_t nb_bufs)
+{
+	int i;
+	struct null_queue *h = q;
+
+	for (i = 0; i < nb_bufs; i++)
+		rte_pktmbuf_free(bufs[i]);
+
+	rte_atomic64_add(&(h->tx_pkts), i);
+
+	return i;
+}
+
+static uint16_t
+eth_null_copy_tx(void *q, struct rte_mbuf **bufs, uint16_t nb_bufs)
+{
+	int i;
+	struct null_queue *h = q;
+	unsigned packet_size = h->internals->packet_size;
+
+	for (i = 0; i < nb_bufs; i++) {
+		rte_memcpy(h->dummy_packet, rte_pktmbuf_mtod(bufs[i], void *),
+					packet_size);
+		rte_pktmbuf_free(bufs[i]);
+	}
+
+	rte_atomic64_add(&(h->tx_pkts), i);
+
+	return i;
+}
+
+static int
+eth_dev_configure(struct rte_eth_dev *dev __rte_unused) { return 0; }
+
+static int
+eth_dev_start(struct rte_eth_dev *dev)
+{
+	dev->data->dev_link.link_status = 1;
+	return 0;
+}
+
+static void
+eth_dev_stop(struct rte_eth_dev *dev)
+{
+	dev->data->dev_link.link_status = 0;
+}
+
+static int
+eth_rx_queue_setup(struct rte_eth_dev *dev, uint16_t rx_queue_id,
+		uint16_t nb_rx_desc __rte_unused,
+		unsigned int socket_id __rte_unused,
+		const struct rte_eth_rxconf *rx_conf __rte_unused,
+		struct rte_mempool *mb_pool __rte_unused)
+{
+	struct rte_mbuf *dummy_packet;
+	struct pmd_internals *internals = dev->data->dev_private;
+	unsigned packet_size = internals->packet_size;
+
+	if (rx_queue_id != 0)
+			return -ENODEV;
+
+	internals->rx_null_queues[rx_queue_id].mb_pool = mb_pool;
+	dev->data->rx_queues[rx_queue_id] =
+		&internals->rx_null_queues[rx_queue_id];
+	dummy_packet = rte_zmalloc_socket(NULL,
+			packet_size, 0, internals->numa_node);
+	if (dummy_packet == NULL)
+		return -ENOMEM;
+
+	internals->rx_null_queues[rx_queue_id].internals = internals;
+	internals->rx_null_queues[rx_queue_id].dummy_packet = dummy_packet;
+
+	return 0;
+}
+
+static int
+eth_tx_queue_setup(struct rte_eth_dev *dev, uint16_t tx_queue_id,
+		uint16_t nb_tx_desc __rte_unused,
+		unsigned int socket_id __rte_unused,
+		const struct rte_eth_txconf *tx_conf __rte_unused)
+{
+	struct rte_mbuf *dummy_packet;
+	struct pmd_internals *internals = dev->data->dev_private;
+	unsigned packet_size = internals->packet_size;
+
+	if (tx_queue_id != 0)
+			return -ENODEV;
+
+	dev->data->tx_queues[tx_queue_id] =
+		&internals->tx_null_queues[tx_queue_id];
+	dummy_packet = rte_zmalloc_socket(NULL,
+			packet_size, 0, internals->numa_node);
+	if (dummy_packet == NULL)
+		return -ENOMEM;
+
+	internals->tx_null_queues[tx_queue_id].internals = internals;
+	internals->tx_null_queues[tx_queue_id].dummy_packet = dummy_packet;
+
+	return 0;
+}
+
+
+static void
+eth_dev_info(struct rte_eth_dev *dev,
+		struct rte_eth_dev_info *dev_info)
+{
+	struct pmd_internals *internals = dev->data->dev_private;
+
+	dev_info->driver_name = drivername;
+	dev_info->max_mac_addrs = 1;
+	dev_info->max_rx_pktlen = (uint32_t)-1;
+	dev_info->max_rx_queues = (uint16_t)internals->nb_rx_queues;
+	dev_info->max_tx_queues = (uint16_t)internals->nb_tx_queues;
+	dev_info->min_rx_bufsize = 0;
+	dev_info->pci_dev = NULL;
+}
+
+static void
+eth_stats_get(struct rte_eth_dev *dev, struct rte_eth_stats *igb_stats)
+{
+	unsigned i;
+	unsigned long rx_total = 0, tx_total = 0, tx_err_total = 0;
+	const struct pmd_internals *internal = dev->data->dev_private;
+
+	memset(igb_stats, 0, sizeof(*igb_stats));
+	for (i = 0; i < RTE_ETHDEV_QUEUE_STAT_CNTRS &&
+			i < internal->nb_rx_queues; i++) {
+		igb_stats->q_ipackets[i] =
+			internal->rx_null_queues[i].rx_pkts.cnt;
+		rx_total += igb_stats->q_ipackets[i];
+	}
+
+	for (i = 0; i < RTE_ETHDEV_QUEUE_STAT_CNTRS &&
+			i < internal->nb_tx_queues; i++) {
+		igb_stats->q_opackets[i] =
+			internal->tx_null_queues[i].tx_pkts.cnt;
+		igb_stats->q_errors[i] =
+			internal->tx_null_queues[i].err_pkts.cnt;
+		tx_total += igb_stats->q_opackets[i];
+		tx_err_total += igb_stats->q_errors[i];
+	}
+
+	igb_stats->ipackets = rx_total;
+	igb_stats->opackets = tx_total;
+	igb_stats->oerrors = tx_err_total;
+}
+
+static void
+eth_stats_reset(struct rte_eth_dev *dev)
+{
+	unsigned i;
+	struct pmd_internals *internal = dev->data->dev_private;
+
+	for (i = 0; i < internal->nb_rx_queues; i++)
+		internal->rx_null_queues[i].rx_pkts.cnt = 0;
+	for (i = 0; i < internal->nb_tx_queues; i++) {
+		internal->tx_null_queues[i].tx_pkts.cnt = 0;
+		internal->tx_null_queues[i].err_pkts.cnt = 0;
+	}
+}
+
+static void
+eth_queue_release(void *q __rte_unused) { ; }
+static int
+eth_link_update(struct rte_eth_dev *dev __rte_unused,
+		int wait_to_complete __rte_unused) { return 0; }
+
+static struct eth_dev_ops ops = {
+		.dev_start = eth_dev_start,
+		.dev_stop = eth_dev_stop,
+		.dev_configure = eth_dev_configure,
+		.dev_infos_get = eth_dev_info,
+		.rx_queue_setup = eth_rx_queue_setup,
+		.tx_queue_setup = eth_tx_queue_setup,
+		.rx_queue_release = eth_queue_release,
+		.tx_queue_release = eth_queue_release,
+		.link_update = eth_link_update,
+		.stats_get = eth_stats_get,
+		.stats_reset = eth_stats_reset,
+};
+
+static int
+eth_dev_null_create(const char *name __rte_unused,
+		const unsigned numa_node,
+		unsigned packet_size,
+		unsigned packet_copy)
+{
+	const unsigned nb_rx_queues = 1;
+	const unsigned nb_tx_queues = 1;
+	struct rte_eth_dev_data *data = NULL;
+	struct rte_pci_device *pci_dev = NULL;
+	struct pmd_internals *internals = NULL;
+	struct rte_eth_dev *eth_dev = NULL;
+
+	RTE_LOG(INFO, PMD, "Creating null ethdev on numa socket %u\n",
+			numa_node);
+
+	/* now do all data allocation - for eth_dev structure, dummy pci driver
+	 * and internal (private) data
+	 */
+	data = rte_zmalloc_socket(name, sizeof(*data), 0, numa_node);
+	if (data == NULL)
+		goto error;
+
+	pci_dev = rte_zmalloc_socket(name, sizeof(*pci_dev), 0, numa_node);
+	if (pci_dev == NULL)
+		goto error;
+
+	internals = rte_zmalloc_socket(name, sizeof(*internals), 0, numa_node);
+	if (internals == NULL)
+		goto error;
+
+	/* reserve an ethdev entry */
+	eth_dev = rte_eth_dev_allocate(name);
+	if (eth_dev == NULL)
+		goto error;
+
+	/* now put it all together
+	 * - store queue data in internals,
+	 * - store numa_node info in pci_driver
+	 * - point eth_dev_data to internals and pci_driver
+	 * - and point eth_dev structure to new eth_dev_data structure
+	 */
+	/* NOTE: we'll replace the data element, of originally allocated eth_dev
+	 * so the nulls are local per-process */
+
+	internals->nb_rx_queues = nb_rx_queues;
+	internals->nb_tx_queues = nb_tx_queues;
+	internals->packet_size = packet_size;
+	internals->packet_copy = packet_copy;
+	internals->numa_node = numa_node;
+
+	pci_dev->numa_node = numa_node;
+
+	data->dev_private = internals;
+	data->port_id = eth_dev->data->port_id;
+	data->nb_rx_queues = (uint16_t)nb_rx_queues;
+	data->nb_tx_queues = (uint16_t)nb_tx_queues;
+	data->dev_link = pmd_link;
+	data->mac_addrs = &eth_addr;
+
+	eth_dev->data = data;
+	eth_dev->dev_ops = &ops;
+	eth_dev->pci_dev = pci_dev;
+
+	/* finally assign rx and tx ops */
+	if (packet_copy) {
+		eth_dev->rx_pkt_burst = eth_null_copy_rx;
+		eth_dev->tx_pkt_burst = eth_null_copy_tx;
+	} else {
+		eth_dev->rx_pkt_burst = eth_null_rx;
+		eth_dev->tx_pkt_burst = eth_null_tx;
+	}
+
+	return 0;
+
+error:
+	if (data)
+		rte_free(data);
+	if (pci_dev)
+		rte_free(pci_dev);
+	if (internals)
+		rte_free(internals);
+	return -1;
+}
+
+static inline int
+get_packet_size_arg(const char *key __rte_unused,
+		const char *value, void *extra_args)
+{
+	const char *a = value;
+	unsigned *packet_size = extra_args;
+
+	*packet_size = (unsigned)strtoul(a, NULL, 0);
+	if (*packet_size == UINT_MAX)
+		return -1;
+
+	return 0;
+}
+
+static inline int
+get_packet_copy_arg(const char *key __rte_unused,
+		const char *value, void *extra_args)
+{
+	const char *a = value;
+	unsigned *packet_copy = extra_args;
+
+	*packet_copy = (unsigned)strtoul(a, NULL, 0);
+	if (*packet_copy == UINT_MAX)
+		return -1;
+
+	return 0;
+}
+
+static int
+rte_pmd_null_devinit(const char *name, const char *params)
+{
+	unsigned numa_node;
+	unsigned packet_size = default_packet_size;
+	unsigned packet_copy = default_packet_copy;
+	struct rte_kvargs *kvlist;
+	int ret;
+
+	RTE_LOG(INFO, PMD, "Initializing pmd_null for %s\n", name);
+
+	numa_node = rte_socket_id();
+
+	kvlist = rte_kvargs_parse(params, valid_arguments);
+	if (kvlist == NULL)
+		return -1;
+
+	if (rte_kvargs_count(kvlist, ETH_NULL_PACKET_SIZE_ARG) == 1) {
+
+		ret = rte_kvargs_process(kvlist, ETH_NULL_PACKET_SIZE_ARG,
+				&get_packet_size_arg, &packet_size);
+		if (ret < 0)
+			return -1;
+	}
+
+	if (rte_kvargs_count(kvlist, ETH_NULL_PACKET_COPY_ARG) == 1) {
+
+		ret = rte_kvargs_process(kvlist, ETH_NULL_PACKET_COPY_ARG,
+				&get_packet_copy_arg, &packet_copy);
+		if (ret < 0)
+			return -1;
+	}
+
+	RTE_LOG(INFO, PMD, "Configure pmd_null: packet size is %d, "
+			"packet copy is %s\n", packet_size,
+			packet_copy ? "enabled" : "disabled");
+
+	return eth_dev_null_create(name, numa_node, packet_size, packet_copy);
+}
+
+static struct rte_driver pmd_null_drv = {
+	.name = "eth_null",
+	.type = PMD_VDEV,
+	.init = rte_pmd_null_devinit,
+};
+
+PMD_REGISTER_DRIVER(pmd_null_drv);
-- 
1.9.1